Brush



Dec. 14, 1937.

,c. c. GERHARDT BRUSH Filed May 29, 1931 I fladult'llllllilll.

v INVENTOR BY HIS ATTO Patented Dec. 14, 1937 aim ersr

4 Claims.

This invention relates to brushes and particularly to rotary brushes and a general object of the invention is to provide a simple and rugged brush construction that can be employed in making brushes for various purposes and that is particularly useful for'rotary wire brushes such, for example, as those employed in the cleaning of boiler tubes.

In the design of a rotary brush, and particularly in the design of a rotary wire brush which is subjected to heavy duty, as in the removal of scale from the interiors of the tubes of water tube boilers, it is important that the steel wire bristles be so sustained by the brush body that they are not easily bent or displaced and it is likewise important that the brush be provided with a sufficient number of bristles to insure distribution of the strain and to insure sufiicient durability of the brush so that it is not necessary to replace the brush too frequently.

Various brushes have been designed for the purposes for which the present brush construc tion is particularly adapted and many of these work very satisfactorily and can be usedfor a large number of cleaning operations. Most of the prior constructions, however, are limited as to the number of bristles that can be incorporated in a brush of a given diameter by reasonof the construction of the means for retaining the bristies in place. An important object of the present invention, therefore, is an improved brush construction in which the means for retaining the bristles in position is so constructed and arranged that a larger number of bristles can be incorporated in the brush construction than in those heretofore commonly used.

Another important feature of the invention is the arrangement of the parts so that they can be very quickly and easily assembled, thereby reducing the cost of manufacture, and so that, furthermore, they can be correspondingly easily disassembled when it is desired to re-equip the brush with new bristles, a further important feature of the invention being the fact that the parts are so secured together that substantially all of the parts of the brush construction except the bristles may be used again when the brush is reconditioned.

Another object of the invention is to provide a rotary brush which is so constructed that the parts which impart rotation thereto may be, for the most part, separate from the brush, thus making it unnecessary to supply more than the brush construction proper when selling the brushes for use with mechanisms for driving them such, for example, as the electric motors and flexible shaft drives provided with boiler tube cleaning equipment. To this end the invention aims to provide a brush construction in which the bristles are so arranged that the brush may readily be provided with a hollow shaft-receiving center.

Other objects and important features of the invention will appear from or be pointed out in the following description and claims when 10 considered in connection with the accompanying drawing in which- Figure l is an end elevation, looking from the left of Fig. 3, of a brush embodying the present invention V Figure 2 is a transverse section through the brush;

Figure 3 is a longitudinal section on the line 3-3 of Fig, l;

Figure 4 is a plan view of a double tuft of bristles before the tuft is preformed showing the manner of uniting the bristles of the tuft;

Figure 5 is an end view of the tuft shown in Fig. 4;

Figure 6 is a section on the line 6-6 of Fig. 3,

and

Figure 7 is an exploded perspective showing the slotted brush body and the removable end.

In the illustrative preferred embodiment of the invention, the brush body or bristle supporting 30 structure 2 is preferably formed, as shown in Fig. '7, by drilling out the center of a cylindrical piece of steel or other suitable material to provide space 3 for receiving the U bends of the bristle tufts 4, hereinafter to be described, and 35 then slotting the cylinder toprovide a plurality 'of bristle-receiving slots 6 separated by segments 8 of the body structure, these slots being preferably uniformly spaced about the periphery of the body 2 and opening through one end of the body 40 2 to permit ready insertion of the bristles.

In the preferred embodiment of the invention, the body 2 of the brush is provided with a shaftreceiving hole ill in its unslotted end, this hole Ill being countersunk, as shown at I2 in Fig. 3, to allow the end of the bushing l4 to be expanded or spun into holding relation thereto.

The bristles to be inserted into the slots 6 ofthe brush are in this preferred embodiment preformed into U-shaped double tufts 4 which 59 straddle the segments 8 so that one of the tufts 4 will be located in one of the slots 6 and the other tuft 4 will be located in another slot 6. This arrangement permits the slots 6 to be substantially completely filled with bristles. 5

In preparing the tufts 4 for insertion in the slots 6, an elongated bundle of wires, if a wire brush is to be formed, such as shown in Fig. 4, and several wires deep, as shown in end view in Fig. 5, may advantageously have its wires or bristles secured together at points intermediate between their ends as, for example, by means of solder it uniting all of the wires into one double tuft. It will readily be understood that the solder may be applied to an individual bundle of substantially rectangular cross section such as shown in Fig. 4, or that the solder may be successively applied at spaced points along a long bundle of wires of the same rectangular cross section, passing the point of application and the double tufts then severed from the bundle.

The wires or bristles which form the tufts 4, having been secured together as shown in Fig. 4, may be then preformed into the U shape shown in end view in Fig. 2, although it will be understood that in the case of some kinds of bristles such preforming will not be necessary but the double tuft may be bent into its U shape at the time it is inserted into the slots 6 in the body 2. The open center 3 provided by boring out the body 2 permits the ready insertion of the tufts of bristles in the slots. It will be understood, of course, that this center may be merely big enough to allow such insertion of the bristles and that the brush body may then be connected in any suitable way to its driving means. In the preferred embodiment of the invention, however, the tuft-receiving opening 3 in the center of the body 2 is sufficiently large to permit a removable shaft ii! to be passed through the center of the brush between the U bends ofv the tufts 4 and preferably also to receive a bushing M to serve as a bearing for the brush on this removable shaft l8.

To secure the tufts of bristles in the slots 6 of the brush body 2, an end member 20 is provided which is advantageously removable, e. g. of the construction shown in Fig. 7, that is, provided with openings 22 shaped to fit over and receive the respective ends of the segments 8, and with a central countersunk bushing receiving hole 24.

From an inspection of Fig. 3 of the drawing, it will be seen that when the tufts of bristles 4 are assembled in the slots 6 of the body 2 and the end piece 20 has been pressed into position over the segments 8 to clamp the bristles, the bushing l4 may be expanded into the countersunk part l2 of the opening I!) in the body 2 at one end and into the countersunk opening 24 in the end piece 29, at its other end, either by spinning or by reaming or by otherwise enlarging its end, thus clamping the end piece 20 tightly against the ends of the tufts 4 and securing the bristles firmly in the brush body, the bushing l4 serving to back up the U bends of the double tufts 4 and to prevent the bristles from being pushed into the body structure when the brush is in use.

To provide for driving the brush against resistance, the unslotted end of the body 2 may be provided with openings 26 which receive pins 28 projecting from the shoulder 30 of the driving shaft 13, the shaft l8 may also be provided with an enlarged screw-threaded extension 32 by which it may be connected to the usual flexible driving shaft or other means by which the rotating power is to be applied to the brush. The end of the shaft l8 projecting beyond the other end of the brush is threaded to receive a nut 34 by which the brush may be clamped securely upon the shaft l8.

From the foregoing description it will be seen that the present invention provides a simple, easily assembled rotary brush construction presenting, for the same dimensions, more than the usual number of bristles and adapted to be built in a great variety of sizes, and particularly in the small diameters so important for cleaning the small diameter tubes used in some of the modern water tube boilers. It will further be seen that when the bristles of the brush have become worn so that the effectiveness of the brush has been diminished, it may easily be reconditioned by simply removing the central bushing I 4, withdrawing the bristle tufts 4 from the slots 6 in the body 2 and inserting new tufts of bristles, the only part of the body structure that may need replacing being possibly the bushing I4.

Although the brush body of the preferred embodiment of the invention has the slots'S formed in an integral structure, it will be understood that the invention may be embodied in structures in which the parts are not integral and that various modifications of the construction and arrangement of the parts may be obtained without dcparting from the fundamental concept.

What is claimed as new is:

1. A rotary wire brush comprising a brush body having an open center, slots extending lengthwise of said body and connecting the periphery with said open center, tufts of U-shaped bristles contiguous in said slots from end to end, each bristle having one leg of its U in one slot and the other leg in another slot and adjacent bristles of each tuft being connected at their U bends independently of the brush body.

2. A brush comprising a hollow body having longitudinal slots intercommunicating and transverse to one another, groups of U-shaped bristles each leg of each group substantially filling a substantial length of one of the slots, and means securing together the bristles of each group independently of the body of the brush, which means is adapted to be engaged by the brush body so as to resist withdrawal of the bristles axially thereof from the slots.

3. A brush as defined in claim 2, in which the bristles are of wire and the means of securing the bristles together is a matrix of solder thicker than the slot through which the bristles of the group pass.

4. A rotary brush comprising, in combination, a rotary brush body having slots about its periphery extending lengthwise from one end and opening into a common interior space, said brush body having an end adapted to close the ends of said slots and removable topermit end access to the slots, tufts of U-shaped bristles filling said slots from end to end, each bristle having one leg of its U in one slot and the other leg in another slot, and adjacent bristles of each tuft being connected at their U bends to form a U-shaped unit capable of ready insertion and removal as a unit into and from said brush body.

CHARLES C. GERHARDT. 

